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Chlorophyceae: Volvocales: Volvocaceae
Chlamydophyceae: Chlamydomonadales: Haematococcaceae
Volvocida: Chlamydomonadina: Stephanosphaeridae

Stephanosphaera sp.
Cohn 1852

Genus: Colony spherical or slightly ellipsoidal in shape, several protoplasts embedded within a gelatinous matrix, covered by a single cellwall; number of protoplasts 8 or 16, rarely 4; a single cell stage is quite similar to Haematococcus; protoplasts, horizontally arranged in circle, vertically parallel; when number of protoplasts is 16, cells arranged as stack of two "circles"; each protoplast elongated ellipsoidal, cylindrical, or ovoid; same as Haematococcus, many filaments protruded from entire protoplast to periphery of the cellwall; two flagella extending outside from protoplast through cellwall; chloroplast parietal, essentially cup-shaped, but adjusted to the shape of protoplast; two pyrenoids present arranging side by side or tandem; stigma rounded, located at posterior part of protoplast; several contractile vacuoles present; accumulation of haematochrom not observed (Süßwasserflora von Mitteleuropa 9, Chlorophyta I, 1983).

Stephanosphaera sp. ?? or similar species, cell body 12-13 μm long, 9 μm wide, gelatinous sheath spherical, 34 μm in diam., x 640, Otto-Numa (pond) Chosei-chi, Tsuchiura city, Ibaraki Pref., Japan, July 2002 by Y. Tsukii
scale 31 μm scale 63 μm scale 94 μm; x 640
Stephanosphaera Stephanosphaera Stephanosphaeras

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